Merge "Merge remote-tracking branch 'origin/5.6' into 5.7" into refs/staging/5.7

1 files changed, 15 insertions, 1 deletions

diff --git a/Source/WebKit/qt/WidgetApi/qwebframe.cpp b/Source/WebKit/qt/WidgetApi/qwebframe.cpp
index e8faab881..dd08725eb 100644
--- a/Source/WebKit/qt/WidgetApi/qwebframe.cpp
+++ b/Source/WebKit/qt/WidgetApi/qwebframe.cpp
@@ -910,7 +910,21 @@ void QWebFrame::print(QPrinter *printer) const
     Evaluates the JavaScript defined by \a scriptSource using this frame as context
     and returns the result of the last executed statement.
 
-    \sa addToJavaScriptWindowObject(), javaScriptWindowObjectCleared()
+    \note This method may be very inefficient if \a scriptSource returns a DOM element
+    as a result. For example, evaluation of the next innocuously looking code may take
+    a lot of CPU and memory to execute:
+
+    \code
+        var img = document.createElement('img');
+        document.getElementById(\"foo\").appendChild(img);
+    \endcode
+
+    This code returns appended DOM element, which is converted to QVariantMap
+    containing all its properties. To avoid this issue you can add "true" after
+    the last statement.
+
+    \sa addToJavaScriptWindowObject(), javaScriptWindowObjectCleared(),
+    QWebElement::evaluateJavaScript()
 */
 QVariant QWebFrame::evaluateJavaScript(const QString& scriptSource)
 {